Apparatus for generating alternating currents.



J. L. MILTON. APPARATUS FOR GENERATING ALTERNATING CURRENTS.

APPLICATION FILED JAN.30,1909,

2 SHEETS-SHEET 1.

Patented Feb. 11, 1913.

1I1v5n DP duhn W111 511 J. L. MILTON. APPARATUS FOR GENERATING ALTERNATING GURBENTS.

APPLIOATICN IILED JAN. 30, 1909v 1,053,107, Patented Feb. 11,1913.

2 SHEETS-SHEET 2.

I, 'n 1.1. L? a W urna 5 JOHN LEWIS MILTON, OF CHICAGO, ILLINOIS.

APPARATUS FOR GENERATING ALTERNATING CURRENTS.

Specification of Letters Patent.

Patented Feb. 11, 1913.

Application filed January 30, 1909. Serial No. 42'5171.

To all whom it may concern Be it known that I. JOHN L. Mimon, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois. have invented a certain new and useful Improvement in Apparatus for Generating Alternating Currents, of which the following is a full. clear, concise. and exact description. reference being had to the accompanying drawings. forming a part of this specification.

My invention relates to a method of generating alternating currents. and an apparat-us adapted to carry my method into operation.

The particular object of my inventmnus to provide a method and means for producin}: alternating currents in connection with the opt-ration of "ga engines. That is to say, the alternating currents are used for sparking purposes to ignite the combustible mixtures.

In order to. facilitate an mulerstauding of my method o'Pgemi-ating alternating currents, I shall first describe a form of apparatus which I have devised for carrying out the various steps involved in my new method,-the understanding being. of course, that the particular form of apparatus shown is for the sake. of illustration upon the scope of my invention as embodied in my novel method of generating alternating currents.

Referring to the drawings, Figure 1 is a trout. View of one form of inducto'-alteruator suitable for carrying out my method, the inductor being shown in its'normal or nitial position; Fig. 2 is a similar View of the sa me structure, the inductor being shown in the position in which it appears at. the moment'of release: Fig. 3 isa similar \itBW oi the same structure showing the position which the inductor assumes upon release under the influence of the springs.

The permanent. magnets 1, shown in the drawings as straight-bar magntts. are at. their ends secured to the ends of pole pieces 2 and 3. To facilitate connection between the magnets and the pole pieces. the

ends of the magnets may be fOlli-Slltlptitb so as to embrace snugly the end portions of the pole pieces, as indicated in Fig. l. Bands 4 may be used 'or clamping the magnets together. It, will be understood. of course, that the pole piece 2 connects poles of like polarity t0gether,say, for instance,

the north poles of the magnetswhile the pole piece 3 connects the other like poles together, as for instance, the south poles.

The pole piece 2 is provided with three polar projections 5, 6 and 7, while the pole piece 3 is provided with corresponding polar project-ions 5'. t3 and 7. The polar projections 6 and (3' carry windings 8 and 8. respectively, while the other four polar projections are unwound. Mounted to more in proximity to the polar projections is the inductor 9 secured to a suitable supporting shaft 9; In the instance illustrated. the shape of the inductor is that of a Maltese cross. haying diametrically opposite arms 10, 10 and 11, 11'. Firmly seated on the shaft 9' is the arm 12,,provided with a pro jection 13. livoted to this arm is a rod 14, which, as shown in Figs. 2 and 3, carries at its outer end head 15. A compression spring 16 is situated between the collars 18 and 19 on the rod 14. The collar 19 is fixed on the rod, while the collar 18 is slidable thereon. The rod 14 works through an aperture in the contact arm 2t). which'is plyotally mounted on a shaft or stud 21. The arm 20 has an extension 22, which carries the movable contact 23, the l'atter e0 operating with the fixed contact 2i on the support 25. lictnoyably secured to the projection 13 on the arm 12 is a piece of hard metal, such as steel, 26, which is adapted to be engaged by the end of the reciprocating rod 27. This rod is connected with the crank shaft of the engine in any suitable way,

and is provided with a cam piece 28. By

means of the set screw 29 the position of this cam piece on the rod :27 may be adjusted. A roller 30 is disposed in the path of the cam member 28. whereby the latter will ride over the surface of the roller in order to break connection at the proper moment between the arm 12 and the rod 2?, as will be presently described. An expansion spring :21 is at one end secured to the pole piece at and at its other end secured to the induct r 9 at 33. Similarly, the expansion spring 3% is at one end sot-ured to the pole piece 3 at 35 and at its other end secured to the inductor 9 at. 36. The connections between the pole pieces and the inductor by means of the springs are such that the initial or normal position of the inductor will be that. indicated in Fig. 1. That is to say, the arms 10 and 10' are in. proximitv to the wound polar projec- 'netic short circuit, thus decreasing the numtion's and (3. respectively. but are out of l alinement theriwvith, whereby a substantial short circu t of the magnetic flux thr ugh the windings 5- pretented. It. will be observed that thi direct connection ol the springs to the polar pieces and the indi -tor is a very simple and etl'eetive one. and I consid r it one of the novel features of the 1 form oi inductor-alternator herein llti\\ll. t From the ahov e t'lescription cl the dev ice herein set-forth. the various steps eoinprisl ing nay new n'icthml of generating high tension currents will now be readily underi 'stood, and i shall titeretcre i roceed with an t explanation of my method. ttsahuveslattal. the red 27 is suitably connectml with the crank shaft of the engine so that during the operatit-n of the cngine'the rod 2T will be moved to the lel't into contact with the cn gaging piece on the arm \Vilh the parts in their normal or initial pusithh. at shown in Fig. 1, the reciprocating rod 27 l will be moved to the left until a l'tt-r a certain interval it will be in the position shown in Fig. 2, from which it seen that the cam member 28 has ridden over the roller 30 and raised the rod ili' until the forward end thereof is just about to break engagement with the contact piece it; of the arm 12. Upon comparison of the position of the inductor as shown in Fig. l with its position as shown in Fig. 2. it will be seen that in be ing moved into what might be termed its operatiie position against the action of the springs 31 and 3%. the inductor first caused a substantial magnetic short circuit through the windings 8 and 8 at the moment when the arms 10 and 10' were in alinement with the polar projections 6 and 6, respectively; then, the inductor being forcedout of such alinement, partially interrupted such mag ber of magnetic lines through the windings 8 and 8, until it finally reached the posi-' tion shown in'Fig. 2. Now when the iii-- ductor has reached this position, it is released by the breaking of engagement between the rod 27 and the arm 12, whereupon the springs 31 and 3t assert themselves and quickly move the inductor into the position in which it is shown in Fig. Comparing the position of the inductor as shown in Fig. 2 with its final position as shown in Fig. 3, it will be noticed that during its travel under the action of the springs the inductor first (3ll (.(l a magnetic short cin cult through the windings S and h" at the moment when th arms 10 and 10" were in alinemcnt with the polar projections t3 and 6, respectively: and then inuncdiately the inductor assumed its final position as shown in Fig. 3, in which position. it will be seen. the magnetic short circuit through the windings is at the moment of interruption.

With regard to the action 01' the comprcs- 1 rated. as shown in Fig.

sion spring li on the rod it it will be nip served that when the arm lL! is forced t the left from the ])t=. lil n in which it i shown in Fig. l to that in which it; Fig. :l. the sprina'l i will he coiiipWsrr-l. thus helding the arm i tnw'aitl the left. where y the contacts 2 and ll will be iii-nil held t gether. llowc'tcr, when the 1 engagement lit'l ween the arm I: and the rod :4 is l l't'li ll. and the indu tor unwed into i the position in which it is shown in Fig. 3. i the head l5 on the rod l i will conic into vio lent c ntact with the upper end of the arm 20. forcing the latter quickly t the right. whereb the contacts Q-l and ill arc sepzn Thi separation ol' the cntacts whi h cause an opening of j the citcuit in which the winding and are included. takes place u -tantially at the molt-cut when the magnetic short circuit is broken: that is to ay. when the inductor in in the pcsition in which it is shown in Fig. I). is is well tunlerstnod. the breaking of the ircn' path for the llux when the inductor has reached the position in which it is shown in Fig. 3 generates a current of hi h electroinotire force. which surging through the ignition circuit leaps across the sparking terminals to ignite the combustible mixtures in the cylinders of the gas engine. The inductor will. of cours not retain the positi n in which it is shown in Fig. 3 folthe reason that that pcsition is due to the moirent of inertia of the inductor and the moving parts connected therewith. whereby the sudden acticn oi the springs carries the inductor beyond its normal position. The extreme position of the inductor, as shown in Fig. 3. more or less only nioinentary and it will immediately assume its normal position. as shown in F g. 1. under the influs ence of the springs. I wish to call particular attention to the position of the inductor as it is shown in Fig.

I discovered in experimenting with a ma chine constructed substantially as herein described that if the inductor be quickly car ried, as is the case when it is operated by an engine at full speed from its initial position. as shown in Fig. 1. into a'position in which the arms 10 and 10 are in alinement with the polar projections (l and 6' and then released, the result was a very feeble spark. lfpon investigation 1 found that by using a very strong pair of springs the spark would be increased, when the inductor was operated by the engine at full speed, and that by using a weaker pair of springs the spark would. underlhe same circumstances, not be perceptible. But if theinductor Was slowly brought: to the above-mentioned position in which the arms 10 and 10 are in alinement with polar projection Sand 6, or if it was brought quickly into this position and then allowed to rest for a moment sult in a very powerful spark. However,

these conditions of operation do not obtain in the practical use of a gas engine, espespeed, and where there would be no period of rest for the engine, such as is' mentioned in the-preceding sentence. However, even with the'use of weak springs upon carrying the inductor beyond .the position in which it causes a substantial magnetic short circuit into a position suchlas that shown in Fig. 2, where the short circuit is at least partially interrupted, and then releasing the inductor,

the result was the production of a very 7 and 8, so that the efl'ective electromotive powerful spark, at all speeds of operation of the engine. Now, as I comprehend it, the

differencein the result obtained by operating the machine in" the several ways as just described is due to "the fact that in the first instance the electromotive force generated during the backward movement of the inductor'had to spe/nd itself largely in overcoming or neutralizing the high self-induced electromotive force which was set up when the'inductor (operated by the engine at full speed) quickly caused a substantial magnetic short-circuit through the windings 8 force was considerably small ,as compared with the generated electromotive force. However, by carrying the inductor beyond a position of alinementwith the polar projections 6 and 6 into a position, such as shown in Fig. 2, in which the magneticshortcircuit has been partially and suificiently interrupted, there is generated an electromotive force which opposes or cuts down the high self'induced electromotive force set up v at the momentof the magnetic short circuit Th result of this cutting down or partial neu alizatio-n of that high self-induced electro otive force is} that upon again establishing the magneticcircuit and immediately interrupting it, the electromotive force generated at the moment of interruption might, be said to encounter a clear field,-that is to say, it does not have to weaken itself in op posing or killing ofi a high counter electromotive force surging through the windings.

As will be seen,'th1s method of operation permits the use of very weak springs, which are highly desirable for mechanical reasons.

It will thus be seen upon an examination of the different positions in which the inductor is shown in Figs. 1, 2 and 3- during the operation ofthe device that the method which I have invented for generatin hi'gh induction currents consists first in increas-* ing the number of, magneticlines through magnetic Isort-circuit through the, win

decreasing the number of mag-T A netic lines through the windings inorder to generate a self-induced electromotive force that will kill off the self-induced electromotive force which was set upby the current generated at the moment of the magnetic cially 'on automobiles where'the speed of the 1 engine varies between low speed and full short-circuit, momentarily stopping the n'iagnetic changes here before reversal, and then suddenly increasing and decreasing in quick succession the number of magnetic lines through the windings, the result of these various steps being the generation of a higl-r tension current sul'licic'nt to produce sparks of considerable magnitude.

Of course it is understood, as I have already indicated, 'that the formof apparatus herein described is only illustrative of apparatus that may be employed to carry my method-into operation, and that so far as the method is concerned other forms and modifications may be devised to carry my invention into effect.

As concerns the construction of the par ticular embodiment of inductor-alternator herein set forth, I do not wish to be confined to any of the details thereof any more than is described in the appended claims. It should be clear. for instance, that my novel arrangement of the springs and their connections with the nloving and stationary parts of the inductor-alternator may be employed with various other forms of' field str ucture-and inductors, and still fall within the scope'of my invention as defined in certain of the claims.

In my copending application, Serial No.- 443508, filed July 15, 1908, I claim matter which is disclosed but not claimed in this application, to wit, the generally circular contour of the field magnet structure with respect to the axis of the rotor.

Havingthus described my invent ion, what I claim as new and desire to secure by Let ters Patent of the United States is:

. 1. An inductor'alternator comprising, in combination, a vmagnetic field-frame provided with oppositely disposed pole-pieces, each of said pole-pieces having three polar projections, windings on the middle projections, aninductor mounted to move between said polar projections and provided with through said windings, spring-means secured. to said inductor and said field-frame for normally holding the inductor'in a predetermined position relative to said 'polar projections, and means forperiodically moving said inductor out of its normal position against the action of said spring-means, whereby said inductor will upon release move in the reverse direction under the ac tio'nlof said'spring-means.

2. An inductoraltcrnawr comprising, in combination, a magnetic field-frame provided with oppositely disposed pole-pieces,

each of said pole-pieces having three) polar project-ions; "windings on the middle projections-ail i' idi-ict-or 'n iounted to move between said polar projections and provided with four radial arms to vary themagnet'ie flux through said windings, a. pair of oppositely disposed sprmgs secured each at one end to said inductor and at its other end to said field-frame for normally holding the inductor in a predetermined position relative to said polar projections, and means for periodically moving said inductor out-0f itsnormeLposition against the action of said springs, whereby said vinductor "will upon releasemovein the reverse direction-under t-he action of said springs.

35A inductor-alternator comprising, in

' combination, a, magnetic. field-frame providedfwitllfuf pair .of polar projections hari'ng windings thereon, a movable inductor having a pair of radial arms to co-act' with saidpolar projections for rnrying the magnetic flux through said windings, spring connections between said inductor andsaid field-frame for normally holding the iii- .ductor-arms in proximity to said polar project-ionsbut' out of alinement, therewith, and

means for periodically moving said in-'- ductor-arnis i nt o'. zilinement with said pro ectI nsend end such position, whereby sa d inductorrwilluponreleasemove in the reverse direction gunder the action, of said spring comlot-ion to generate "a Qspa'rking current, v

ii we. f

i 's'i'tely exte polar projec ions,

A ndue comb nation ,a mEJg'neti -fieIdJriIme prodiametrically opposite ms coactfwith said .1784? urgthe magnetic e inetoricornprising, in

mgvwindings thereon, linv ngnipsir of oppositely disposed spring-connections between said inductor and said field-frame for normally holding the inductor-arms in prox imity to said polar projections but out of alinemerit therewit-lnand means for periodically moving said inductor-arms. into alinement with said projections and beyond such 7,

position, whereby saidinductor will upon release more in the reverse direction under the notion of said spring-connections to generate a sparking-current.

5. An inductor-alternator comprising, in combination, a msigneti cj field-frame provided with oppositely disposed pole-pieces,

o eaclrof said pole-pieces having three polar ment' therewith,end means for periodically moving said induct/or out of its normal -po-' come into-refinement with said middle polar projections andthenpass beyond such post-- ition, whereby said inductor will" upon releasemove in a reversedireotion' and genernew sparking-curr t 7 r #In witness whereof,

' Q NLEM$ PT \Nithesses: I? LEO-mini) I, Novnzpnn, .A. A,Tnolimsl"""' p I hereunto subscribe i ginyneme' this 22nd day-of January, 

